chore: custom content types design groundwork

docs/design/states.md

@@ -54,6 +54,19 @@ Glossary pass 2, changes made: activity log lines "Removed N expired invites" an
 | 404 site_not_found (sitemap) | GET /v1/site/{key}/sitemap, unknown key. The body is the code `site_not_found`, shown on Integration in the code style (not rewritten as prose). |
 | 400 (sitemap page or size) | "The request cannot be processed due to a mismatch in the format of the body." (same text as the other routes on Integration) |
 | 403 owner_only vs article SEO | Integration note under the 403 row: "Site SEO defaults are owner only. Article SEO fields need only the right to edit the article." |
+| 404 content_type_not_found | Page: "Content type not found · It may have been deleted, or the address may be mistyped." |
+| 404 entry_not_found | Page: "Entry not found · It may have been deleted by someone else." |
+| 409 content_type_key_taken | Under the key: "The key "events" is already used by another content type. Choose a different key." |
+| 409 content_type_has_entries | Delete dialog: "Recipes now has entries · Someone added an entry after this page loaded, so nothing was deleted. Delete the entries first, then try again." |
+| 400 invalid_content_type_key | Under the key: "Use 2 to 40 lowercase letters, digits or hyphens." |
+| 400 invalid_field | On the marked field, per rule (label, key, limits, default, choices). If the client missed one: "Check the fields marked in the list." |
+| 409 schema_incompatible | Refusal dialog: "Nothing was changed · RenewCMS refused the changes because some entries don't fit the new fields. It doesn't say which entries." |
+| 422 invalid_entry: key: required | "Fill in Title." (date: "Pick a date for Starts on.", choice: "Choose an option for Category.") |
+| 422 invalid_entry: key: type | "Title must be text." / "must be a number." / "must be yes or no." / "must be a date, like 2026-11-21." |
+| 422 invalid_entry: key: min, max | Text: "needs at least N characters", "can be up to N characters". Number: "must be at least N", "must be at most N". Date: "can't be before D", "can't be after D" |
+| 422 invalid_entry: key: options | "Choose one of: Talk, Workshop or Meetup." |
+| 409 invalid_entry: key: unique | "Another entry already uses this Title. Enter a different one." plus the alert "Not saved" |
+| 422 invalid_entry: key: unknown_field | Alert "The fields of Events changed", button Reload form |
 | 500 – | "Couldn't save the site. Your changes are still here. Try again in a moment." / "Couldn't save the author. Your changes are still here. Try again in a moment." / "Couldn't create the author" / "The article is unchanged. Try again in a moment." (notice inside the panel or dialog) |
 
 ## Public image 400 bodies
@@ -79,3 +92,15 @@ screens/<name>.md, section "Copy per state" (generated from the board source).
 
 ## SEO round
 Frames: Editor: search and sharing (24), Editor: what the frontend gets (6), Sites: SEO defaults (5), Articles: search status (3). Each is drawn desktop and mobile; light and dark follow the theme switch. None is clock-sensitive: dates in the API preview are fixed sample values. Disabled state: all fields at 40% while saving. Validation: slug taken, canonical not absolute, title template without %title%, excerpt over 300. Suggestions never block saving or publishing. Copy per state: screens/editor.md, articles.md, sites.md.
+
+
+## Custom content types
+Groups on `RenewCMS Screens Schema.dc.html`: 1 Schema list (6), 2 Schema builder (16), 3 Review and delete (7), 4 Field types (6), 5 Content and entry list (9), 6 Entry editor (13), 7 Relations (3), 8 Permissions (2), 9 Export and import (3). 65 states, 56 available now and 9 later. Each has a 1440 and a 390 frame; light and dark follow the theme switch. Nothing is clock-sensitive. Tag per state: "Available now" or "Later". Copy per state: screens/schema.md, content.md, entry.md, schema-later.md.
+
+Roles: owners and admins see Schema and edit types. Any verified user sees the Content group and reads and writes entries. A user who is not owner or admin and opens /schema gets "You don't have access to Schema".
+
+Keys: a type key is 2 to 40 lowercase letters, digits and hyphens (chosen at creation, never changes). A field key is lowercase letters, digits and underscores, starts with a letter, up to 40 (editable until its field is first saved). The two inputs show their own rule.
+
+Schema changes with entries: Save opens the review ("Add 2 fields, change 1, remove 1"); Apply sends the PUT; schema_incompatible shows "Nothing was changed" and names the kind of change that likely caused it, never an entry. A type with entries cannot be deleted ("You can't delete Events yet").
+
+Entry rules, 422 except unique (409): required, type, min, max, options, unique, unknown_field. Messages are per type and drawn in the field-type gallery (group "Field types").